Proceedings Volume 6559

Enhanced and Synthetic Vision 2007

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Proceedings Volume 6559

Enhanced and Synthetic Vision 2007

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Volume Details

Date Published: 27 April 2007
Contents: 6 Sessions, 22 Papers, 0 Presentations
Conference: Defense and Security Symposium 2007
Volume Number: 6559

Table of Contents

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Table of Contents

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  • Front Matter: Volume 6559
  • Session 1
  • Session 2
  • Session 3
  • Session 4
  • Poster Session
Front Matter: Volume 6559
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Front Matter: Volume 6559
This PDF file contains the front matter associated with SPIE Proceedings volume 6559, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.
Session 1
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Concept of operations for the use of synthetic vision system (SVS) display during precision instrument approach
Synthetic Vision Systems (SVS) create images for display in the cockpit from the information contained in databases of terrain, obstacles and cultural features like runways and taxiways, and the known own-ship position in space. Displays are rendered egocentrically, from the point of view of the pilot. Certified synthetic vision systems, however, do not yet qualify for operational credit in any domain, other than to provide enhanced situation awareness. It is not known at this time whether the information provided by the system is sufficiently robust to substitute for natural vision in a specific application. In this paper an operations concept is described for the use of SVS information during a precision instrument approach in lieu of visual contact with a runway approach light system. It proposes an operation within the existing framework of regulations, and identifies specific areas that may require additional research data to support certification of the proposed operational credit. The larger purpose is to set out an example application and intended function which will require the elaboration and resolution of operational and human performance concerns. To this end, issues in several categories are identified.
Synthetic vision systems: operational considerations simulation experiment
Lynda J. Kramer, Steven P. Williams, Randall E. Bailey, et al.
Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.
EGPWS on synthetic vision primary flight display
Gang He, Thea Feyereisen, Kevin Conner, et al.
This paper describes flight tests of a Honeywell Synthetic Vision (SV) Primary Flight Display prototype system integrated with Enhanced Ground Proximity Warning System (EGPWS). The terrain threat information from EGPWS system is displayed with synthetic vision terrain background in a coordinated 3D perspective-view and 2D lateral map format for improved situation awareness. The flight path based display symbology provides unambiguous information to flight crews for recovery and avoidance with respect to the threat areas. The flight tests further demonstrate that the SV based display is an effective situation awareness tool to prevent crew blunder in low visibility situations and further backup the accident chain that typically proceeds control flight into terrain (CFIT) accidents.
Human factors evaluation of a dynamic channel depiction of navigation procedures in SVS displays
C. Pschierer, J. Schiefele, D. Howland, et al.
Synthetic vision systems (SVS) are studied for some time to improve pilot's situational awareness and lower their workload. Early systems just displayed a virtual outside view of terrain, obstacles or airport elements as it could also be perceived through the cockpit windows in absence of haze, fog or any other factors impairing visibility. Required digital terrain, obstacle and airport databases have been developed and standardized by Jeppesen as part of the NASA Aviation Safety Program. Newer SVS displays also introduced different kinds of flight guidance symbology to help pilots to improve the overall flight precision. The method studied in this paper is to display navigation procedures in the form of guidance channels. First releases of the described system used static channels, generated once at the startup at the system or even offline. While this approach is very resource friendly for the avionics hardware, it does not consider the users, which want the system to respond to the current flight conditions dynamically. Therefore, a new application has been developed which generates both the general channel trajectory as well as the channel depiction in a fully dynamic way while the pilot flies a navigation procedure.
Fused enhanced and synthetic vision system (EVS/SVS) for low-visibility operations
Carlo Tiana, Robert Hennessy, Keith Alter, et al.
We present an Integrated Multisensor Synthetic Imaging System (IMSIS) developed for low-visibility, low-level operations, tailored to Army rotorcraft. IMSIS optimally avails itself of a variety of image-information sources: FLIR, mm-Wave RADAR and synthetic imagery are all presented to the flying crew in real time, on a fused display. Synthetic imagery is validated in real time by a 3D terrain sensing radar, to ensure that the a priori stored database is valid, and to eliminate any possible aircraft positioning errors with respect to the database. Extensive human factor evaluations were performed on the fused display concept. All pilots agreed that IMSIS would be a valuable asset in reduced visibility conditions and that the validated SVS display was rated nearly as flyable as a good FLIR display. The pilots also indicated that the ability to select and fuse terrain information sources was an important feature. IMSIS increases situational awareness at night and in all weather conditions, while considerably reducing pilot workload compared to separately monitoring each sensor and enhancing low-level flight safety by updating the terrain in real time. While specifically designed for helicopter low-level flight and navigation, it can aid hover and touchdown and landing for both fixed and rotary wing platforms as well as aid navigation even in non-airborne domains.
Making a land/go-around decision with runway incursions in near zero-zero weather
David M. Murphy, Douglas J. Zimmer, Guy A. French
Preventing runway incursions is considered a top safety priority for the National Transportation Safety Board and is a growing problem among commercial air traffic at controlled airfields. This problem only increases in difficulty when the weather and airfield conditions become severely degraded. Such is the case in this Air Force Research Laboratory (AFRL) work, which focused on the decision making process of aircrew landing under near zero-zero weather at an unimproved airfield. This research is a part of a larger demonstration effort using sensor technology to land in near zero-zero weather at airfields that offer no or unreliable approach guidance. Using various head-up (HUD) and head-down (HDD) display combinations that included the sensor technology, pilot participants worked through the decision of whether the airfield was safe to land on or required a go-around. The runway was considered unsafe only if the boundary of the runway was broken by an obstacle causing an incursion. A correct decision is one that allowed the aircrew to land on a safe runway and to go-around when an incursion was present. While going around is usually considered a safe decision, in this case a false positive could have a negative mission impact by preventing subsequent landing attempts. In this study we found a combination of display formats that provided the greatest performance without making significant changes to an existing avionics suite.
Flight assessment of an integrated DNAW helicopter pilotage display system: flight trial HAWKOWL
David C. Thorndycraft, Peter J. Longman, David F. Marsden, et al.
Military helicopter operations are often constrained by environmental conditions including low light levels and poor weather. Recent operational experience has also shown the difficulty presented by certain terrain when operating at low altitude by day and night. For example, poor visual cues when flying over featureless terrain with low scene contrast, or obscuration of vision caused by wind blown and re-circulated dust at low level (brown out). These types of conditions can result in loss of spatial awareness and loss of precise control of the aircraft. Atmospheric obscurants such as fog, cloud, rain and snow can similarly lead to hazardous situations. Day Night All Weather (DNAW) systems applied research, sponsored by UK MOD, has developed a systematic, human centred approach, to understanding and developing pilotage display systems for challenging environments. A prototype DNAW system has been developed using an incremental flight test programme, leading to the flight assessment of a fully integrated pilotage display solution, trial HAWKOWL, installed in a Sea King helicopter. The system comprises several sub-systems including; a multi-spectral sensor suite, image processing and fusion; head down and head-tracked Display Night Vision Goggles; onboard mission planning and route generation; precision navigation; dynamic flight path guidance; and conformal, task dependent, symbology. A variety of qualitative and quantitative assessment techniques have been developed and applied to determine the performance of the system and the capability it provides. This paper describes the approach taken in the design, implementation and assessment of the system and identifies key results from the flight trial.
Session 2
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Use of X-band weather radar to support the terrain database integrity monitoring and terrain referenced navigation function
Abhijeet Singh, Maarten Uijt de Haag
To enable safe use of Synthetic Vision Systems (SVS) at lower altitudes, real-time sensor measurements are required to ensure the integrity of terrain and obstacle models stored in the onboard SVS and to detect hazards that may have been omitted from the stored models. This paper discusses various aspects of using X-band weather radar for terrain database integrity monitoring and terrain referenced navigation. Feature extraction methods will be addressed to support the correlation process between the weather radar measurements and the stored terrain databases. Furthermore, improved weather radar antenna models will be discussed to more reliably perform the shadow detection and extraction (SHADE) functionality. In support of the navigation function, methods will be introduced to estimate aircraft state information, such as velocity, from the geometrical changes in the observed terrain imagery. The outputs of these methods will be compared to the state estimates derived from Global Positioning System (GPS) and Inertial Navigation System (INS) measurements. All methods discussed in this paper will be evaluated using flight test data collected with a Gulfstream V in Reno, NV.
Enhanced and synthetic vision system for autonomous all weather approach and landing
Within its research project ADVISE-PRO (Advanced visual system for situation awareness enhancement − prototype, 2003 - 2006) that will be presented in this contribution, DLR has combined elements of Enhanced Vision and Synthetic Vision to one integrated system to allow all low visibility operations independently from the infrastructure on ground. The core element of this system is the adequate fusion of all information that is available on-board. This fusion process is organized in a hierarchical manner. The most important subsystems are a) the sensor based navigation which determines the aircraft's position relative to the runway by automatically analyzing sensor data (MMW, IR, radar altimeter) without using neither (D)GPS nor precise knowledge about the airport geometry, b) an integrity monitoring of navigation data and terrain data which verifies on-board navigation data ((D)GPS + INS) with sensor data (MMW-Radar, IR-Sensor, Radar altimeter) and airport / terrain databases, c) an obstacle detection system and finally d) a consistent description of situation and respective HMI for the pilot.
Towards an inexpensive computer-vision based automated landing system for small unmanned aerial vehicles
Kevin Blenkhorn, Stephen O'Hara
We present a system for UAV automated landing that requires minimal landing site preparation, no additional electronics, and no additional aircraft equipment of any kind. This is a Joint-UAV solution that will work equally well for land-based aircraft and for shipboard recoveries. Our proposed system requires only a simple target that can be permanently painted on a runway, laid out in a roll-up mat, or potentially denoted with chemical lights for night operations. Its appearance is unique when seen from the optimal approach path, and from other angles its perspective distortion indicates the necessary correction. By making continual adjustments based on this feedback, the plane can land in a small area at the desired angle. We time the pre-touchdown flare using only a 2D visual reference. Assuming a constant closing speed, we can estimate the time to contact and initiate a controlled flare at a predetermined interval.
Using perspective guidance overlay to improve UAV manual control performance
Jochum Tadema, Eric Theunissen, Joris Koeners
The guidance information that is available to the UAV operator typically suffers from limitations of data update rate and system latency. Even when using a flight director command display, the manual control task is considerably more difficult compared to piloting a manned aircraft. Results from earlier research into perspective guidance displays show that these displays provide performance benefits and suggest a reduction of the negative effects of system latency. The current study has shown that in case of limitations of data update rate and system latency the use of a conformal sensor overlay showing a perspective presentation of the trajectory constraints is consistently superior to the flight director command display. The superiority becomes more pronounced with an increase in data latency and a decrease in update rate. The fact that the perspective pathway overlay as used in this study can be implemented on any graphics system that is capable of rendering a set of 2-D vectors makes it a viable candidate for upgrades to current systems.
Session 3
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Design and testing of an unlimited field-of-regard synthetic vision head-worn display for commercial aircraft surface operations
Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down, electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were their monochrome form and limited, fixed field of regard. A potential solution to these limitations found with HUDs may be emerging Head Worn Displays (HWDs). HWDs are small, lightweight full color display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized for commercial aviation applications. In the proposed paper, the results of two ground simulation experiments conducted at NASA Langley are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to enhance transport aircraft surface operations. The two studies tested a combined six display concepts: (1) paper charts with existing cockpit displays, (2) baseline consisting of existing cockpit displays including a Class III electronic flight bag display of the airport surface; (3) an advanced baseline that also included displayed traffic and routing information, (4) a modified version of a HUD and EMM display demonstrated in previous research; (5) an unlimited field-of-regard, full color, head-tracked HWD with a conformal 3-D synthetic vision surface view; and (6) a fully integrated HWD concept. The fully integrated HWD concept is a head-tracked, color, unlimited field-of-regard concept that provides a 3-D conformal synthetic view of the airport surface integrated with advanced taxi route clearance, taxi precision guidance, and data-link capability. The results of the experiments showed that the fully integrated HWD provided greater path performance compared to using paper charts alone. Further, when comparing the HWD with the HUD concept, there were no differences in path performance. In addition, the HWD and HUD concepts were rated via paired-comparisons the same in terms of situational awareness and workload. However, there were over twice as many taxi incursion events with the HUD than the HWD.
Challenges with displaying enhanced and synthetic vision video on a head-up display
Displaying video on a head-up display from an Enhanced Vision System camera or Synthetic Vision System engine presents some unique challenges not seen on conventional head-down flight deck displays. All information displayed on the HUD has to be seen against a background that can vary from bright sunlight to a dark night sky. The video has to include enough grayshade information to support visual identification of runway features and the image shown on the HUD has to be visually aligned to the real world accurately enough to support low-visibility operations at airports. The pilot needs to clearly see the image on the HUD but also needs to see the real world through the display when it can be seen with the naked eye. In addition, the video display cannot interfere with the display of existing flight information symbology.
Calibration and display of distributed aperture sensor systems
Distributed aperture sensor (DAS) systems can enhance the situational awareness of operators in both manned and unmanned platforms. In such a system, images from multiple sensors must be registered and fused into a seamless panoramic mosaic in real time, whilst being displayed with very low latency to an operator. This paper describes an algorithm for solving the multiple-image alignment problem and an architecture that leverages the power of consumer graphics processing units (GPU) to provide a live panoramic mosaic display. We also describe other developments aimed at integrating high resolution imagery from an independently steerable fused TV/IR sensor into the mosaic, panorama stabilisation and automatic target detection.
The use of configural displays to promote pilot situation awareness
Previous research has shown that the use of configural displays allows people to more easily detect changes in dynamic processes for integration tasks thereby enhancing operator performance, yet the benefit of configural displays on operator situation awareness (SA) has yet to be assessed. To test whether or not the use of configural displays impacts the formation of pilot SA, a computer-based study was undertaken using two presentation rates (500ms and 1000ms) and three configural display formats (Mil-Std-1787 HUD, Dual-articulated (DA) HUD, and the Arc Segment Attitude Reference (ASAR)) to present aircraft flight reference information to pilots. One of five questions were possible following the removal of the display from the screen, a query about aircraft airspeed, altitude, flight path angle (climb or dive) or bank angle. The aim of the study was to demonstrate the ability to provide an increase in operator SA by utilizing emergent features in configural displays to increase cue saliency and thereby increase operator SA. The analysis of pilots' recall of aircraft flight path angle (percent correct) showed that pilots were significantly more aware of aircraft attitude with the ASAR than with either the MIL-STD 1787 or DA HUD formats. There was no difference among displays for recall of actual flight path angle (RMS error). The results are discussed in terms of the use of configural displays as a design approach in representing task goals to facilitate operator SA.
Session 4
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Prevention of runway incursions due to closed runways or unsuitable runway choices by enhanced crew situational awareness and alerting
Christoph Vernaleken, Carole Urvoy, Uwe Klingauf
Of all incidents on the aerodrome surface, Runway Incursions, i.e. the incorrect presence of an aircraft on a runway, are the by far most safety-critical, resulting in many fatalities if they lead to an accident. A lack of flight crew situational awareness is almost always a causal factor in these occurrences, and like any Runway Incursion, the special case of choosing a closed or unsuitable runway - including mistaking a taxiway for a runway - may have catastrophic consequences, as the Singapore Airlines Flight SQ006 accident at Taipei in 2000 and, most recently, Comair Flight 5191, tragically show. In other incidents, such as UPS Flight 896 at Denver in 2001 departing from a closed runway or China Airlines Flight 11 taking off from a taxiway at Anchorage in 2002, a disaster was only avoided by mere luck. This paper describes how the concept for an onboard Surface Movement Awareness and Alerting System (SMAAS) can be applied to this special case and might help to prevent flight crews from taking off or landing on closed runways, unsuitable runways or taxiways, and presents initial evaluation results. An airport moving map based on an ED-99A/DO- 272A compliant Aerodrome Mapping Database (AMDB) is used to visualize runway closures and other applicable airport restrictions, based on NOTAM and D-ATIS data, to provide the crew with enhanced situational awareness in terms of position and operational environment. If this is not sufficient to prevent a hazardous situation, e.g. in case the crew is distracted, a tailored alerting concept consisting of both visual and aural alerts consistent with existing warning systems catches the crew's attention. For runway closures and restrictions, particularly those of temporary nature, the key issue for both extended situational awareness and alerting is how to get the corresponding data to the aircraft's avionics. Therefore, this paper also develops the concept of a machine-readable electronic Pre-flight Information Bulletin (ePIB) to bring relevant NOTAM information to the flight deck prior to the flight, with a possibility to receive updates via data link while the aircraft is airborne.
Compact self-contained enhanced-vision system (EVS) sensor simulator
We describe the model SIM-100 PC-based simulator, for imaging sensors used, or planned for use, in Enhanced Vision System (EVS) applications. Typically housed in a small-form-factor PC, it can be easily integrated into existing out-the-window visual simulators for fixed-wing or rotorcraft, to add realistic sensor imagery to the simulator cockpit. Multiple bands of infrared (short-wave, midwave, extended-midwave and longwave) as well as active millimeter-wave RADAR systems can all be simulated in real time. Various aspects of physical and electronic image formation and processing in the sensor are accurately (and optionally) simulated, including sensor random and fixed pattern noise, dead pixels, blooming, B-C scope transformation (MMWR). The effects of various obscurants (fog, rain, etc.) on the sensor imagery are faithfully represented and can be selected by an operator remotely and in real-time. The images generated by the system are ideally suited for many applications, ranging from sensor development engineering tradeoffs (Field Of View, resolution, etc.), to pilot familiarization and operational training, and certification support. The realistic appearance of the simulated images goes well beyond that of currently deployed systems, and beyond that required by certification authorities; this level of realism will become necessary as operational experience with EVS systems grows.
Flight assessment of a real time multi-resolution image fusion system for use in degraded visual environments
M. I. Smith, J. R. E. Sadler
Military helicopter operations are often constrained by environmental conditions, including low light levels and poor weather. Recent experience has also shown the difficulty presented by certain terrain when operating at low altitude by day and night. For example, poor pilot cues over featureless terrain with low scene contrast, together with obscuration of vision due to wind-blown and re-circulated dust at low level (brown out). These sorts of conditions can result in loss of spatial awareness and precise control of the aircraft. Atmospheric obscurants such as fog, cloud, rain and snow can similarly lead to hazardous situations and reduced situational awareness. Day Night All Weather (DNAW) systems applied research sponsored by UK Ministry of Defence (MoD) has developed a multi-resolution real time Image Fusion system that has been flown as part of a wider flight trials programme investigating increased situational awareness. Dual-band multi-resolution adaptive image fusion was performed in real-time using imagery from a Thermal Imager and a Low Light TV, both co-bore sighted on a rotary wing trials aircraft. A number of sorties were flown in a range of climatic and environmental conditions during both day and night. (Neutral density filters were used on the Low Light TV during daytime sorties.) This paper reports on the results of the flight trial evaluation and discusses the benefits offered by the use of Image Fusion in degraded visual environments.
Applying daytime colors to night-time imagery with an efficient color transfer method
Guangxin Li, Ke Wang
We propose a color transfer method to give fused multiband nighttime imagery a natural daytime color appearance in a simple and efficient way. Instead of using traditional &rhookl;&agr;&bgr; space, the proposed method transfers the color distribution of the target image (daylight color image) to the source image (fused multiband nighttime imagery) in a linear color space named IUV. The transformation between RGB and IUV spaces is simpler than that between RGB and &rhookl;&agr;&bgr; spaces, moreover, the IUV space is more suitable for image fusion. The IUV transform can be extended into a general formalism. We prove that color spaces conforming to this general IUV framework can produce same recoloring results as IUV space. Our experiments on infrared and visual images show that the IUV based color transfer method works surprisingly well for transferring natural color characteristics of daylight color images to false color fused multiband nighttime imagery. We also demonstrate that this method can be successfully applied to a variety of images. The images generated indicate the potential utility of IUV space in color image processing domains.
Semantic bifurcated importance field visualization
Eric Lindahl, Plamen Petrov
While there are many good ways to map sensual reality to two dimensional displays, mapping non-physical and possibilistic information can be challenging. The advent of faster-than-real-time systems allow the predictive and possibilistic exploration of important factors that can affect the decision maker. Visualizing a compressed picture of the past and possible factors can assist the decision maker summarizing information in a cognitive based model thereby reducing clutter and perhaps related decision times. Our proposed semantic bifurcated importance field visualization uses saccadic eye motion models to partition the display into a possibilistic and sensed data vertically and spatial and semantic data horizontally. Saccadic eye movement precedes and prepares decision makers before nearly every directed action. Cognitive models for saccadic eye movement show that people prefer lateral to vertical saccadic movement. Studies have suggested that saccades may be coupled to momentary problem solving strategies. Also, the central 1.5 degrees of the visual field represents 100 times greater resolution that then peripheral field so concentrating factors can reduce unnecessary saccades. By packing information according to saccadic models, we can relate important decision factors reduce factor dimensionality and present the dense summary dimensions of semantic and importance. Inter and intra ballistics of the SBIFV provide important clues on how semantic packing assists in decision making. Future directions of SBIFV are to make the visualization reactive and conformal to saccades specializing targets to ballistics, such as dynamically filtering and highlighting verbal targets for left saccades and spatial targets for right saccades.
Poster Session
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Surveillance video with spatially registered graphics for decision support
Anthony Majoros, John Ianni, Paul Davies, et al.
Conventional daylight video, and other forms of motion imagery, have an expanded role in communication and decision making as sensor platforms (e.g., unoccupied aerial vehicles [UAVs]) proliferate. Video, of course, enables more persons to become observers than does direct viewing, and presents a rapidly growing volume of content for those observers to understand and integrate. However, knowing the identity of objects and gaining an awareness of situations depicted in video can be challenging as the number of camera feeds increases, or as multiple decision makers rely on the same content. Graphic additions to streaming video, spatially registered and appearing to be parts of the observed scene, can draw attention to specific content, reduce uncertainty, increase awareness of evolving situations, and ultimately produce a type of image-based communication that reduces the need for verbal interaction among observers. This paper describes how streaming video can be enhanced for decision support using feature recognition and tracking; object identification, graphic retrieval and positioning; and collaborative capabilities.